Elevated leukocyte counts are common and are associated with increased risks
Elevated leukocyte counts increase the risk of thrombosis1
- Risk is clearly increased in patients with leukocyte counts >7 x 109/L
- Risk becomes statistically significant when the count is ≥11 x 109/L (HR=3.90; 95% CI, 1.24-12.3; P=0.02)
Elevated leukocyte counts2

- In a retrospective chart review of 1080 patients currently receiving HU, 58.2% had elevated leukocyte counts (>10 x 109/L)2
Elevated leukocyte counts may increase risk of thrombosis by 70%3
- Supplemental phlebotomy does not reduce leukocyte or platelet counts in PV4